Relativistic Signatures of Flux Eruption Events Near Black Holes

Understand

Images of supermassive black holes produced using very long baseline interferometry provide a pathway to directly observing effects of a highly curved spacetime, such as a bright ``photon ring'' that arises from strongly lensed emission.

• In addition, the emission near supermassive black holes is highly variable, with bright high-energy flares regularly observed.
• We demonstrate that intrinsic variability can introduce prominent associated changes in the relative brightness of the photon ring.
• We analyze both semianalytic toy models and GRMHD simulations with magnetic flux eruption events, showing that they each exhibit a characteristic ``loop'' in the space of relative photon ring brightness versus total flux density.